New York, Jan 2 (IANS): Pre-existing depression or anxiety disorders and the use of psychoactive drugs may increase an individual's risk of long-term use of opioid pain medication, a study has found.

"We found that pre-existing psychiatric and behavioural conditions and psychoactive medications were associated with subsequent claims for prescription opioids," said Patrick D. Quinn from Indiana University in Bloomington, US.

The association was stronger for long-term opioid use, especially for patients with a previous history of substance use disorders, the researchers said.

The results showed that harmful outcomes of opioid use substance use disorders, depression, suicidal or self-injuring behaviour and motor vehicle accidents were also predictors for long-term opioid drug use.

The study showed that nearly 1.7 per cent of patients with opioid prescriptions become long-term opioid users (six months or longer), but the risk was substantially higher for patients with mental health conditions or psychoactive medication use.

Rates of increase of long-term opioid use ranged from 1.5 times for patients taking medications for attention-deficit/hyperactivity disorder (ADHD), three times for previous substance use disorders and nearly 9 times for previous opioid use disorders.

"Our results add to existing evidence that the risk of long-term opioid receipt associated with [pre-existing] psychiatric and behavioural conditions is widespread and relates to multiple diagnoses and psychoactive medications," Quinn said.

"The study supports the idea that clinical practice has deviated from the 'careful selection' under which most clinical trials are conducted and that thorough mental health assessment and intervention should be considered in conjunction with the use of long-term opioid therapy," he added.

For the study, published in the journal PAIN, the team examined 10.3 million patients who filed insurance claims for opioid prescriptions between 2004 and 2013.